Firefox has a page reader in Reader View. Reader View simplifies many kinds of pages. On pages that are compatible with this feature, you can turn it on by clicking the icon near the right end of the address bar that looks like a document. Then use the toolbar to the left of the article to read the page. See: View web pages in Reader View.

If you need something to read web pages in their standard format, maybe there is an add-on for that.

Since you are on Windows, you can use the system's Windows Narrator feature.